Re: [PATCH 4/4] genirq/irq_sim: shrink code by using cleanup helpers

[Yury Norov]

On Sat, Aug 12, 2023 at 09:44:57PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> 
> Use the new __free helper from linux/cleanup.h to remove all gotos and
> simplify the error paths.
> 
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> ---
>  kernel/irq/irq_sim.c | 24 ++++++++++--------------
>  1 file changed, 10 insertions(+), 14 deletions(-)
> 
> diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
> index a8b013d0c5be..202beb1169c9 100644
> --- a/kernel/irq/irq_sim.c
> +++ b/kernel/irq/irq_sim.c
> @@ -4,6 +4,7 @@
>   * Copyright (C) 2020 Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
>   */
>  
> +#include <linux/cleanup.h>
>  #include <linux/interrupt.h>
>  #include <linux/irq.h>
>  #include <linux/irq_sim.h>
> @@ -170,34 +171,29 @@ static const struct irq_domain_ops irq_sim_domain_ops = {
>  struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
>  					 unsigned int num_irqs)
>  {
> -	struct irq_sim_work_ctx *work_ctx;
> +	struct irq_sim_work_ctx *work_ctx __free(kfree) = NULL;
> +	unsigned long *pending __free(bitmap) = NULL;

Why initializing here as NULL ...
  
>  	work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
>  	if (!work_ctx)
> -		goto err_out;
> +		return ERR_PTR(-ENOMEM);
>  
> -	work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
> -	if (!work_ctx->pending)
> -		goto err_free_work_ctx;
> +	pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
> +	if (!pending)
> +		return ERR_PTR(-ENOMEM);

and overriding immediately after that? Not familiar to __free()
machinery in details, although. Does it require initialization?

Thank,
Yury